1. Field of the Invention
The present invention relates to crustacea peeling apparatus and more particularly relates to a crustacea peeling device which cuts the tail of crawfish on each side of the tail along the edges so that the upper and lower tail exoskeletal portions can easily separate to expose the contained meat product.
2. General Background
Many crustaceans are edible food products that are typically consumed by removing the hard exoskeleton so that the softer meat product can be consumed. Common crustaceans that are used on a nation wide basis as a food product includes of course crabs, lobsters, and some parts of the country, crayfish or crawfish. In in the Southeastern Gulf Coast area, and more particularly in the states of Louisiana, Mississippi and Texas, crawfish are a very important food item which are consumed in vast quantities and, after being cooked in a crab boil, hot sauce or the like, and/or can be included in stews, soups, or fried, for example. While the popularity of crawfish has long existed in a regional portion of the country adjacent the Gulf of Mexico, recently the popularity of Acadian cooking has increased the demand for crawfish.
Several devices have been patented which attempt to process or remove the edible meat from a crustacea tail. U.S. Pat. No. 3,221,363, entitled "Process For Removing The Edible Meats From Crustacea Tails," issued to Couret, provides a process for removing the edible meat from a prawn.
An early patent for picking crayfish is seen in the Roshko U.S. Pat. No. 2,660,754, which uses a machine for separating the meat from the hulls and includes a frame having upper and lower mounted roller members, and the rollers being disposed one substantially vertically above the other with an adjustable tensioning means between the mounting members urging the members together. A water jet spray in front of the apparatus is provided. A continuous rotation is imported to the rollers during operation. The crayfish are fed into the device, tail first one at a time, the head portion of the crayfish having been first removed by hand. As the crayfish enters the device, the hull is cracked and opened with a motion that loosens the meat and the spray from the water jet is directed so that it washes the meat out of the hull, thus assisting the squeezing out action of the rollers. Once the meat is free, the water washes it down over the lower roller and away from the machine, thus preventing any unnecessary mutilation of the separated meat by the rollers. The meat is then caught on the forward side of the machine by a bend, and the hulls are caught in a trough or container at the rear of the rollers.
Some crawfish peeling devices use air pressure as part of the method for removing the meat product from the crustacean shell. In the Ingalls U.S. Pat. No. 3,758,921, entitled "Crawfish Peeler," a machine is provided which automatically peels crawfish or other crustaceans in which the crustacean to be peeled has a head and tail respectively held between grippers on separate conveyors having operative runs which diverge in the direction of their movement. The grippers of the two conveyors are in laterally opposed pairs which are located abreast of and adjacent each other at the loading end of the conveyors to receive the head and tail sections respectively of the crustacean and thereafter separates the head and tail section as they move apart due to the divergence of the operative conveyor runs. The meat retained by the tail section is ejected by shearing off the extremity of the tail section adjacent to movement of the associated conveyor, then injecting a blast of pressurized air into the tail section through the opening formed by such shearing action, and the empty shells are then discharged at the end of each operative run.
Rotary cutting blades are used in the U.S. Pat. No. 3,871,086 issued to Rutledge, entitled "Apparatus For De-Shelling Crustaceans." In the Rutledge patent, de-headed crawfish are passed through parallel cutting blade assemblies composed of concentric blades that may be of equal or unequal height. The apparatus operates by shattering the dorsal shell of the crayfish thus removing the meat product.
A later patent issued to Rugledge, U.S. Pat. No. 4,121,322, entitled "Crustacean Meat Extraction Means" provides a pair of rollers positioned adjacent to one another to form a nip for receiving the crustacean wherein the lower nip is provided with at least one groove for receiving the meat as it is squeezed from the crustacean shell.
A pair of cooperating grooved rollers is described in the Mestayer et al. U.S. Pat. No. 4,196,495, entitled "Crawfish Tail Peeler." The first roller has a concave lateral peripheral edge surface which is opposed at a substantially constant spacing by a convex lateral peripheral edge surface of a second roller, the rollers being rotated in opposite senses to received the exoskeletal portions of the crawfish between the opposing peripheral edge surfaces of the rollers. Rear margins of the flippers of the crawfish are grasped between the counter rotating rollers, the exoskeletal portions covering the tail being pulled between the rollers to peel the exoskeletal portions from the edible portions and to simultaneously devein the crawfish tail.
A more recent U.S. Pat. No. 4,385,422, issued to Ingalls et al., entitled "Crayfish Peeler," provides an apparatus for both de-heading and peeling crayfish comprising pairs of gripper assemblies for operative engagement with the head and tail sections of a crayfish supported for movement in synchronized relation through separate but tangentially related orbits wherein the pairs of grippers simultaneously move in a common direction through or past the point of tangency of their respective orbits wherein the tail holding gripper assemblies each comprise a lower crayfish pan constructed from flexible rubber or plastic having an arcuate cross-section greater than 180.degree. and a top arm member pivotly mounted above the lower pan to hold the crayfish in the pan during the de-heading cycle, the pivoting of top arm member being actuated by a simplied cam assembly. The device uses air pressure to force the meat from the shell of the crustacean.
Many of these prior art devices uses pinch roller arrangements which squeeze or attempt to squeeze the crawfish from the shell. The problem with squeeze rollers is that often the meat itself is damaged along with the shell when the shell is squeezed. Further, the rollers often do not perform as desired wherein they become viscous or fluidized through the accumulation of water upon the rollers during operation. Many of the prior art patents use air pressure in an attempt to force the crawfish from the shell. This is an expensive and cumbersome method in that a timing mechanism must be used to turn on and shut off the air pressure at precisely the correct moment and when the crawfish is properly positioned.